Back-gating

Yes. The neighbors have persuaded the owner to block access for construction traffic. Whereas if we sell the whole property, they can use the back gate. That lane s a byway—public road— even though it s not asphalted. It s all or nothing, I m afraid. ... 

Another example of an Si-based pH sensing device is an electrolyte-insulator-semiconductor (EIS) structure. In a typical EIS sensor, a voltage applied to the semiconductor back gate (Vgate) attracts ions in the electrolyte to the oxide surface. The... 

Fig. I. Analysis of lysed whole blood stained with FITC-anti-CD45 and PE-anti-CD14. (A) Scatter analysis, showing the position of a gate to restrict the analysis to lymphocytes. (B) Gated fluorescence analysis, showing that over 98% of the gated cells are in quadrant 4 (Q4). Monocytes would appear in quadrant 2 (Q2) and nonleukocytes in quadrant 3 (Q3). With suboptimal cell preparations, the position of the lymphocyte scatter gate can be determined by back-gating that is, examining the scatter distribution of cells gated by quadrant 4.

During subsequent data analysis, gate the cells positive for CD45 and negative for CD 14 onto the FSC vs SSC dot plot to refine the optimal position for the lymphocyte scatter gate. This method is known as back-gating ... 

Fig. 6.11. Back-gating from CD 14 fluorescence to determine the scatter characteristics from monocytes. Such back-gating facilitates the placing and then evaluation of a monocyte scatter gate.

By extension from this simple example, the technique of back-gating has been applied quite elegantly to leukocytes by the use of... 

Back-gating Back-gating is a strategy by which the fluorescence of stained cells within a mixed population is used to determine the side scatter and forward scatter characteristics of those cells. This is in contrast to traditional gating, whereby scatter characteristics are used to delineate cells whose fluorescence characteristics are then determined. 

Fig. 1. Orthogonal light scatter (side scatter, SSC) (y-axis) displayed against forward scatter (FSC) (x-axis) for the author s peripheral blood leucocytes. This is in the form of a dot plot. Each dot represents one cell. A gate has been set on the lymphocyte cluster. If there is any doubt, this cluster can be positively identified using a pan-T antibody (anti-CD3) and back-gating, as described in Section 3.2.2. Data were recorded using a Becton-Dickinson FACSCAN.

The most simple pentaeene OTFT test structure used in many labs is based on a Si wafer piece covered with a thermal oxide. Here, the heavily doped Si wafer takes the role of the back gate electrode, and the Si02 takes the role of the gate dielectric. A pentacene thin film is deposited as the semiconducting layer. Source and drain electrodes are deposited either on the silicon oxide (bottom contact) or on top of the pentacene film (top contact). 

Figure 26.6 Model of geometric gate capacitances for (a) back-gated and (b) electrochemically gated SWCNT-FETs. In the case of back-gating, the geometric capacitance is determined by the capacitance of the Si02 dielectric. During electrochemical gating the electro-...

Figure 26.12 A nanotube FET obtained through back-gate assisted selective ECM of SWCNT bundles containing both m- and s-SWCNTs. The gate dependence of conductance initially shows metaUic behaviour (sohd line). After selective ECM, the conductance shows a variation of around five orders of magnitude (dash-dotted hne) signifying that the m-SWCNTs have been eliminated. was 10 mV before ECM and 50 mV after ECM.

In order to avoid this drawback, we have recently developed an alternative ECM scheme which does not require the presence of a back gate and is applicable also to denser networks [52]. This method relies upon the fact that a voltage ViQ applied to an Ag/AgCl liquid gate electrode has the same effect as applying a potential of - to the working electrode (the contacted nanotube)... 

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